HIF-α Activation Impacts Macrophage Function during Murine Leishmania major Infection

Autor: Manjunath Bettadapura, Hayden Roys, Anne Bowlin, Gopinath Venugopal, Charity L. Washam, Lucy Fry, Steven Murdock, Humphrey Wanjala, Stephanie D. Byrum, Tiffany Weinkopff
Jazyk: angličtina
Rok vydání: 2021
Předmět:
Zdroj: Pathogens, Vol 10, Iss 12, p 1584 (2021)
Druh dokumentu: article
ISSN: 2076-0817
DOI: 10.3390/pathogens10121584
Popis: Leishmanial skin lesions are characterized by inflammatory hypoxia alongside the activation of hypoxia-inducible factors, HIF-1α and HIF-2α, and subsequent expression of the HIF-α target VEGF-A during Leishmania major infection. However, the factors responsible for HIF-α activation are not known. We hypothesize that hypoxia and proinflammatory stimuli contribute to HIF-α activation during infection. RNA-Seq of leishmanial lesions revealed that transcripts associated with HIF-1α signaling were induced. To determine whether hypoxia contributes to HIF-α activation, we followed the fate of myeloid cells infiltrating from the blood and into hypoxic lesions. Recruited myeloid cells experienced hypoxia when they entered inflamed lesions, and the length of time in lesions increased their hypoxic signature. To determine whether proinflammatory stimuli in the inflamed tissue can also influence HIF-α activation, we subjected macrophages to various proinflammatory stimuli and measured VEGF-A. While parasites alone did not induce VEGF-A, and proinflammatory stimuli only modestly induced VEGF-A, HIF-α stabilization increased VEGF-A during infection. HIF-α stabilization did not impact parasite entry, growth, or killing. Conversely, the absence of ARNT/HIF-α signaling enhanced parasite internalization. Altogether, these findings suggest that HIF-α is active during infection, and while macrophage HIF-α activation promotes lymphatic remodeling through VEGF-A production, HIF-α activation does not impact parasite internalization or control.
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